Continuous retort



Feb-9, 1943. MGARVEY cLgNE 2,310,215

" CONTINUOUS RET'QRT Filed may 3, 19:59 11 sheets-sheet 1 gmc/Wto@ n Feb. 9,. 1943. MCGARVEY CLINE 2,310,215

CONTINUOUS RETORT I Filed May 3, 1939 A v 11 SheetshSheet 2 Syvum@ We @QV, @5% 5x65, 74M 7L/dor,

Feb. .9, 1943'. MCGARVEY. LINE 2,310,215

CONTINUOUS RETORT Filled May 3, 1959 11 vsnee'cs-sri'eet 3 Feby9, 111943. MeGARvEY CLINE I* `2,310,215

CONTINUOUS RE'roRT Fned'uay 3, i939 -11 sheets-sheet 4 d u v E Wega/11.47%,

Fens, 1943. ,Y MCGAR'VEY CLINE 2,310,215 CONTINUOUS RETORTI Filed 'May 3. 1939 11 Sheets-Sheet 5 Feb. 9, 1943. McGARvl-:Y CLINE 2,310,215

v ACONTINUOUS RETORT A Filed May 3, 1939 11 heeLS-Sheet 6 Feb. 9, 1943. McGARvEY cLlNE 2,310,215 I CONTINUOUS RETORT Filed May 3, 1939 Vl1 Sheets-Sheet'l? Feb. 9, 1943.`

` MCGARVEY CLIN;

CONTINUOUS RETORT Fileduay 3. 1939 1 1 sheets-'sheet 8 Feb."9, 1943` MQGARVEY CLINE 2,310,215

CONTINUQUS RETORT FiledMay 3, 1939 11 Sheets-Sheet 9 u .m .L .mH ::I .,v

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Feb. 9, 1943.

MCGARVEY CLINE CONTINUOUS RETORT 11 sheet-sheet -11 Filed May :5, 1939 Patented Feb. 9, 1943 UNETE S'ATES .arsNr orrics This invention relates to continuous retorts for subjecting materials to the action of heat, and more particularly to retorts in which the heating medium does not come in contact with the materials being processed and where the products resulting from the action of heat on the materials may be readily recovered.

While the invention isk primarily adapted for processing solid materials in finely divided form, it may also be applied to the treatment of certainV concentrated solutions or suspensions. Among the substances which may be treated, are wood in the form of small chips, sawdust or powder; con-` centrated liquors produced inl the paper pulp industry; agricultural waste products such as straw, corn stalks, tobacco stems, wheat'and oat hulls, etc., when such materials are nely divided or shredded; and nut hulls, seed pits, shredded bone, etc. In its broadest aspects, the invention is applicable to the simple drying of materials such as those above mentioned, but it is intended more particularly for the destructive distillation of such materials, whereby they are completely carbonized, and, at the same time, the vapors and gaseous products resultingr from the distillation may be recovered. The invention has special utility when used for the destructive distillation of resincus wood, such as that of the southern pine.

Many eorts have been made to successfully distill the large amount of waste pine wood available in this country both in the form of stumps,` limbs, etc., left in the operation of saw mills, or in the form of nely divided chips produced in the wood naval stores industry and left as a residue after the oleo-resinous materials have been extracted by means of solvents. The destructive distillation of such material, however, has heretofore presented diicult practical problems, owing to the peculiar nature of the material, and it is the general-object of the present invention to devise elective means for carbonizing resinous woods, particularly the spent chips above referred to, with the coincident recovery of valuable products such as phenols and other distillates.

The apparatus of the present invention may be considered as a further development of and improvement on that disclosed in my prior Patent No. 1,763,758, issued June 17, 1930, and while the present invention relates to apparatus of the same general type as that of said patent, it

Athereof; to devise an improved heating element having means for causing the hot gases to flow therethrough more eiectively; to provide improved conveyor elements for handling the material more eiectively; to provide improved means Vfor driving the feeding and discharging mechanism; to provide improved feeding mechanism which will serve .to deliver measured quantities of material into the retort in such a manner as to prevent packing and jamming, and will, at the same time, prevent the escape'of gaseous products; to provide means for separattrolled as desired.

With the above and other objects in view, the invention consists in the construction and arrangement of parts hereinafter describedand claimed, and illustrated in the accompanying drawings forming part of this specication, and in which:

Fig. 1 is a side elevation of my improved retort complete, parts being broken away and parts being shown in section; v

Fig. 2 is a plan viewv on an enlarged scale of the top of the apparatus, parts being omitted for the sake of clearness, and parts being Ybroken away;

Fig. 3 is a horizontal section substantially on the line 3 3 of Fig. 1, but showing parts' not appearing in Fig. 1;

Fig. 4 is a fragmentary, vertical, central section on an enlarged scale through the lower part ofthe apparatus shown in Fig. 1;

Fig. 5 is a similar section on the same scale through the upper part of the apparatus;

Fig. 6 `is a plan view of one of the improved heating elements;

Fig. 7 is a transverse section thereof substantially on the line 1-1 of Fig. 6, lookingin the direction of the arrows;

Fig. 8 is a plan View of the supporting ring on which the lowermost heating element rests; Y Fig. Q-is a transverse section on the line 9 -9 of Fig. 8,' looking in the direction of the arrows; Fig.'10` is av fragmentary side elevation von an enlarged scale, showing two superposed heating elements with one of the conveyor elements between them, and illustrating my improved means for ejecting caked material from the conveyor; Fig. 11 is a plan View of the topmost conveyor element and associated parts; y

' Figs. 112 and 12a together constitute aV transverse section substantially on the line 12A-l2 of Fig. 11, looking in the direction of the arrows, the superposed parts being shown as separated;

Fig. 13 is a fragmentary plan view of one of the series of intermediate conveyor elements which I employ;

Fig. 14 is a central transverse section therethrough;

Fig. 15 is a vertical longitudinal section on an enlarged scale showing the details of the improved feed mechanism illustrated in general in Fig. 1;

Fig. 16 is a vertical transverse section substantially on the line IS-I 6 of Fig. 15, looking in the direction of the arrows;

Fig. 17 is a fragmentary vertical section through the lower part of the apparatus substantially on the line I'I-I'I of Fig. 3;

Fig. 18 is a vertical transverse section substantially on the line IS-IS of Fig. 3, looking in the direction of the arrows;

Fig. 19 is a fragmentary sectional view on an enlarged scale substantially on the line Ill-I9 of Fig. 18, showing details of my improved temperature controlling apparatus; and- Fig. 20 is a horizontal section substantially on the line 26-20 of Fig. 4, looking in the direction of the arrows.

Referring to the drawings in detail, and more particularly first to Fig. 1, my improved apparatus comprises a supporting base A and associated parts, a rotatable vertical cylindrical shell B, constituting the body of the retort, and a stationary top or superstructure C.

Referring now more particularly to Figs. 1 and 4, the base comprises a cylinder I,` preferably made of metal and resting upon a suitable foundation 2. On top of the cylinder I is supported a base plate 3, extending entirely across the apparatus and having an opening therein concentric with the cylinder I.

Supported upon the base plate 3 just above the cylinder I is a ring shaped rail or track 4, on which the rotary cylindrical shell revolves, as hereinafter described.

'I'his shell comprises a lower section 6, to which is secured a horizontal annular flange 5. from which depend an intermediate vertical cylindrical web 'I and an outer concentric web 8 spaced apart as shown. Also secured to the cylindrical section 6 is an angle flange 9, adapted to support a similar flange, secured to the lower end of the main cylindrical shell of the retort.

To the outer wall 8 is secured an angle flange I 0, to the under side of which is secured, by bolts I I, an annular ring gear I2V having teeth on its outer periphery.

Mounted beneath the ring gear I2 and secured thereto as by means4 of some of the bolts II are a plurality of rollers I3 adapted to bear against the outer vertical surface of the ring rail 4.

Secured to the upper surface of the ring gear I2 are a plurality of bearing housings or journal boxes I4, containing bearings in which arerjournalled the spindles of supporting wheels I5, which rest and ride upon the upper surface of the ring rail 4. Thus the weight of the rotary shell is carried by the wheels I5, and it is centered and held against lateral displacement by the rollers I3, bearing against the outer face of the ring rail.

Secured to the base plate 3 at a point just inside of and spaced from the depending web 'I is an upstanding cylindrical web I6, and also secured to the base plate 3y just outside of and spaced from the web l is a similar upstanding cylindrical web I'I. It will thus be seen that the cylindrical webs or rings I6 and I'I form, with the base plate 3, an annular trough into which the depending web or ring 'I extends. This trough is partially filled with some suitable liquid (not shown) into which the web 'I dips so as to form a gas tight seal around the bottom of the retort.

The main body B of the retort comprises a cylindrical shell I9, to the lower edge of which is secured an angle ring I8, mating with and attached to the angle ring 9.

Resting on the base plate 3 is a supporting ring 20, shown as of frusto-conical form, having a horizontal base flange 2l terminating in a short vertical flange 22, which ts snugly within the opening in the base plate 3. This supporting ring is best shown in Figs. 8 and 9, and is adapted to be secured to the base plate 3 by means of bolts passing through holes 2 Ia, which, as shown, are preferably spaced 221/2o apart. This is done so that the supporting ring may be angularly adjusted with respect to the base plate and set in any desired one of sixteen different positions.

At the upper edge of the ring 20 is a groove 23 preferably having tapered sides, as shown, for the purpose of making a tight joint with the lowermost heating element, as hereinafter described.

The ring 204 is provided with an inwardly projecting lug 24, with a series of strengthening webs 25, and with a series of eight pairs of radially extending lugs 26, the purpose of which will be hereinafter explained.

As in my former patent, above referred to, the retort comprises a vertical series or stack of hol low annular heating elements. In the present case, however, these heating elements designated in their entirety by the4 reference numeral 21, are of improved construction, the details of which are best shown in Figs. 6 and '7.

Each annular heating element has, at its lower edge, a conical flange adapted to lit into the groove 23 of the supporting ring 2?), or into a similar groove 32 formed at the upper edge of each heating element, as the case may be, so that when the heating elements are assembled or stacked up in superposed relation, as shown in Figs. 4 and 5, their meeting edges are sealed and their interiors are in continuous communication.

Referring again to Figs. 6 and '7, each improved heating element comprises spaced bottom and top walls 29 and 30, reinforced by radial connecting webs 3|, and are preferably formed by casting. It will be understood that these webs 3l are preferably spaced similar to the webs 25, shown in Fig. 9, each, in the embodiment shown, being 221/2 apart, so that when the superposed elements are assembled in the form of a stack, these strengthening webs will be in vertical alignment throughout the stack. Supported by the webs 3I and extending between the upper and lower walls 29 and 39 in an annular baille 33, of somewhat dished form, as shown. Around the inner periphery of this baiile is a thickened vertically disposed rib or ange 34, extending both above and below the same, and projecting horizontally inward from this thickened rib is a narrow, annular, horizontal flange 35. The inner portion of the baille 33 is preferably provided with a plurality of radially extending slots 36 for permitting expansion and contraction of the bale under changing temperature conditions.

As in my prior patent, each heating element is provided with a notch or sector-shaped opening 3,8 of approximately 221/2 in extent,Y the hollow interior of the heating element being closed by radial walls 39 at either side of this notch.

Each heating element is provided, at its-lower edge, adjacent the said notch, with a downwardly projecting lug 28', adapted to engage the lug 24 onthe base ring 20 (Fig. 8) or to engage a similar lug 24', (Fig. 6) formed at the upper edge of each heating element, so as to angularly position one with respect to the other.

Each heating element 21 is further provided adjacent its upper edge with a series of eight pairs of inwardly projecting radial lugs 31, and adjacent its lower edge with a similar series of eight pairs of inwardly projecting radial lugs 31', the lugs of one series vbeing staggered with respect to those of the other, so that in plan view, as shown in Fig. 6, there is a pair of lugs 221/2 around the inner periphery of the heating element.

From the foregoing, it will be obvious that in assembling the heating elements on the supporting ring 20 and on each other to form a stack, as shown in Figs. 4 and 5, each heating element'may be so positioned thatthe nottch 33 therein is angularly displaced 221/ from the notch in the heating element next below, whereby the notches are arranged in a broken spiral around the stack, and are not in vertical alignment, but offset from each other, as shown in Fig. 10. It will further be understood that, the supporting ring 2U having once been bolted in position with the lug 24 at the desired point, this lug will` determine, by means of the key lug 28' on the heating elements, the angular position of the lowest heating element and the location of the notch 38 therein. The remaining heating elements can then be progressively angularly displaced so that the notches therein define a spiral as above mentioned, the notch in the lowermost heating element being disposed at the left hand side of the apparatus adjacent the discharge mechanism, as shown in Fig. 4, and the notch in the uppermost heating element being disposed almost in the same vertical line but displaced therefrom Aa distance of 221/2" in a counter-clockwise direction, as illustrated in dotted lines in Fig. 2. When the series of heating elements have been assembled on the supporting ring 20, and on each other in superposed relation,y and in the desired relative angular positions, they are secured together by means of bolts 4I passing through vertically aligned pairs of lugs 31' and 26 or 31, as the case may be (see Fig. 4). No attempt has been made to illustrate all of these lugs in Figs. 4 and 5, however, only one or two pairs being illustrated for the sake of clearness.

vOn the under side of each heating element adjacent the opening or notch therein is formed a series of concentric depending ribs 40 having bevelled or inclined lower surfaces 40a, as shown in Fig. l0. The purpose of these ribs Will be hereinafter explained.

As best shown in Figs. 4 and 5, the space between the inner peripheries of adjacent baffles 33 is closed by means of short cylindrical sections or walls 42. The edges of these sections fit within the annular shoulders 34 formed on the baffles and engage and are separated by the radial flanges 35.

It will thus be seen that the cylindrical sectionsA 42 provide a continuo-us, central, vertical ue or conduit extending from the top to the bottom of the stack of heating elements.

' It will further be observed that the cylindrical walls v42 are spaced inwardly from the meetlng edges ofthe heating elements 21, thus providing an annular opening between the interiors of adjacent elements.

Depending from the lower side of the base plate 3 and concentricwith theabove mentioned con- Beneath this opening and the lower end of pipe 45V is a radial duct 46, the purpose of which will hereinafter described. i

The inside of the cylinder 43 and the outside of the pipe 45 are preferably covered with a layer of heat resistant material 41, and this is shownasv continued up through the supporting ring 20 by means of an additional section 48on the top of which rests an annular ring 49, snugly fitting withinvthe lowermost cylindrical section 42. vIt will thus be seen that the pipe 45 and wall 48 forms a continuation of the vertical axial conduit comprising the sections 42, and that this conduit communicates at its lower end with the radial duct 46.

Supported on and forming a tight connection with the uppermost heating element 21 is a top plate having a central opening 5l therein (see Fig. 5) above which opening is secured a cylinder 52 having at its upper end. a detachable cover plate 53.

Tapping the side of the cylinder 43 (see Fig. 4) is a radial conduit 54, connected outside .the base E with an enlarged section 55, both preferably lined with heat resisting material, as shown. 'Ihe enlarged section 55 is connected :at its outer end with a furnace 56, or other source of heat, the hot gases from the furnace preferably passing into the conduit 54, 55 through a delivery nozzle 51 spaced from the Walls of the section 55, as shown.

The furnace conventionally indicated at 56 is preferably of the gas or oil burning type, having at its outer end a suitable fuel inlet 56a and air inlet means'Eib (Fig. 3) whereby hot gases from the furnace are delivered through the nozzle 51 y' into the conduit 54. Any other suitable source of hot gases may, of course, be employed.

, with a clamping nut 61.

Tapping the furnace conduit 55 radially at a point adjacent thenozzle 51 is a pipe 58 (see Figs. 3, 4 and 18), this pipe being connected with a Ty 53 from the upper side of which extends a discharge flue or stack 60. The opposite end of the T 59 is connected with the discharge side of an air pump, shown as a centrifugal fan 6I. A pipe or flue 62 extends from-the intake ofthe fan 6I to the bottom of the retort, Where it connects with a short inclined section 46', communicating at its other end with the ra-dial duct 46 (see Fig. 1'7).v

In the T 59, I provide adjustable means for defiecting any desired portion of the gases delivered from the fan 6l into the outlet or discharge stack 60. As illustrated in Figs. 18 and 19, this deflecting means may consist of a damper 63 secured at 64 to a cross shaft journalled in the Walls of the T, to the outer end of which shaft is attached an operating lever 65, through which passes a clamping bolt having an enlarged head 66, which works freely in an arcuate guide or slotted quadrant 68, the outer end of the bolt being threaded and tted It is obvious that by loosening this nut, vthe lever 65, and with itthe damper 63, may be swung to any desired angular position and then` clamped in such position by tightening the nut. f

Supported by and. movable overv the flaty upper sulface 3ft of each heating element is. an annulacLr conveyor element of improved construction., As clearly shown in Figs; land' 14, this conveyor'element comprises an inner ring 69', an outer angle ring lj, and a series. of' spaced radial bars 'H rigidly.` connecting said rings and forming'. there-` with an annular series of cells closed on all fourY sides.. Thesel conveyor elements are adapted to be-rotated bythe. cylindrical shell' I9 thiough'the` medium. of short drag chains 'l2` attached' at one end to the ring 'Ill and at the other endto the shell. The preferable point of attachment of. these chains is.- to the inner Wall of flanged hand holes oriopenings. T3, as. shown in' Figs; 4 and 5', provided with cover plates lli.

At the bottom of' the retort adjacent and sur-` rounding the supporting ringv 29 is a special' conveyor element' comprising. inner and outer rings 69! and lll! connected by radial bars 1|', these4 bars being considerably deeper thanthe bars. 1|

ofthe. standard conveyor elements, and arranged with. their lower edges just above the base plate 3. This special conveyor element ts snugly Within the. cylindrical section 6, at the bottom of the retort, and is supported on lugs 6a secured tothe inner surface thereof. (See Fig. 4.)

On the topmost heating. element is mountedv another specalconveyor element comprising. an outer angle ring 10a, inverted as compared with the. rings 7), and an inner angle ring E9a (see Figs. 5v and 12). This inner angle ring 69a is disposed with its upper horizontal leg overhanging. the outer edge of the plate 59, as shown..

Extending up from this horizontal leg is a. lug 69g (Fig. l2), the purpose of which willhereinafter: appear.

i Coming now to the. superstructure of the apparatus and referring more particularly to Figs. 2 and 5, I provide a top plate 15, shown as substantially square, and supporti this plate at its opposite. sides upon longitudinal beams 16T, which' beams. may conveniently. constitute part of the. framework of the buildingV or shed in. whichthe.

apparatus is. housed. The' longitudinal. beams 16. rest uponandare connectedby suitably spaced.

cross beams 7:1; as shown.

Depending; from the lower. side of the plate 'l5-f is a cylindrical. web: or. skirt. 'I8 of slightlyV thus forming a uid tight sealat the upper end` of. the rotating shell I9, between such shell and thestationary superstructure associated with the topplate 15. It willbe here observed that-there is` no connection whatever betweenthis superstructurev and other parts of the retort, the super--l structure being supported entirely by the beams or framing 16, l1, and the cylindrical shell I9y freely. rotating beneath the same and. outof contact therewith.

The top plate 'I5 has a. central opening, .from

the inner edge of whiclidepends a circular. shellV 19; concentric with the skirt 18' but spacedl inwardly therefrom. The top plate'TE'has anopening a extending between the elements T8` and 19; asshown in Fig. 5; and at both the front and* rear ofthis opening, as viewed in Fig.. 5; are vertical plates 80, bridging the space between egsrogaie the 'elements '18 and '19,. and? forming therewith` a closed chute; immediately below thev opening. 15a. Above this opening is: a1 housing 8l`,. into which the. material tol be' treated is fed, as hereinafter described.. The top of the housing 8l may be formed with al hand hole provided with V a: removable cover' 8 la.

Extending upwardly from' the top plate 'lli'and registering with the central opening therein and forming a. continuation of, the circular wall' '19, is' a'. cylinder' 82' provided with a' cover plate 83:.

To the bottom of'thecircular wall' 'lil'is'secure'd4 a horizontally'disposed annular plate' 8T. (Figs. 2' andi 5.) At one. point in' itscircumferen'ce. as. shown: at the right. hand side of Fig. 5; the. wall 'I9' is; provided withy anI opening 8'8', which mergesV at its lower. end witha similar opening orn'otch' 88a, formed in the plate 87- (Fig. 2)

Depending from the plate 81 is a curved' di'- agonally extending scraper. blade 89', the purpose of which. will be herenatter'described..

Referring to. Figs. 5, 11. and' 12a, I provide` aA rotary member comprising. an. annular plate` 90,. having.' a dependingV peripheral ange. 91,. to thel upper' side of which. plate. is secured a. vertical cylinder 92 having an. internal flange 93 at the: upper. endv thereof, such. cylinder' beingV of substantially'less diameter than the plate 90'.. The: inner` edge ofthe annular plate- 90? makes free sliding' contact with thev stationary cylinder 52'.

When assembled, the lowerV edge of' the flangei 954? ofi theplate 90 rests upon4 and is supportedi bythe' upper horizontal leg of' the angle' ring 69a; and inside-ofthe iiange 9L' is formed. a lug` 90e' (Fig. 122e)- which is adapted to engage'- ther lug 69h (Fig. 121) so' that the plate 9U andassociated parts are caused to. rotate' with. the con-- veyorelement comprisingtheJ angle ring 69'. The plate 90 iscentered and heldi againstsub'- stanti'al lateral displacement by means ofi the. cylinder 52.

The rotary cylinder 92' is of suchsize as to make a free sliding itl within the annular plate` 87.

Itwill now beY apparent-that the: elementsf19,

i 81 andiV 92 together form anlannulartrough,- the bottom andi outer walls of which areistationaryI and the inner wall-of which rotates.

Rigidly secured to the flange 931 at the' toplo'i-` the cylinder 92y isaVA pair of' Scrapers, eachvco'mprising-A a' bracket S11-with blades 94e and 94!" eX'-= tending upwardly andA downwardlytherefrom. ((Figs; l`1- and 12a.) Strengthening-ribs4 95 pref'- erab'lyVA connect thebladeswith the brackety9'4.

By' reference to Fig. 5; it will:r now be seen that the edges 9d of the bladesSYi travelini close' proximity'to the-inner surface of'the cylindrical chamber- 82 and that the lower edges 94 ofthe'V blades 94hwork in close proximity to the annular platev 8T constituting the'y bottom of the trough; above'referred to.- When, therefore, the Scrapers revolve, the blades scrape fromthe in-y ner Walls of' the cylindrical chamber any solid matter.' which has been deposited thereon. solidAA matterA falls' by gravity into the trough above' described, andis moved along theb'ottom B'Ithereof by means of the scraper blades andY discharged downwardly through the opening 88a' therein (Fig. 2). The discharged material fallsV 'upon' the' annular plate 90 (Fig. 5) from which-it is'swept4 outwardly' by the scraper 89 andis deposited into the upper conveyor element comprising the rings ga'andlllff.

Extending radially out from the cylindrical chamber 32 'is a discharge-pipe-96A for the gases" Feeding mechanism The improved means which I have devised for feeding the finely divided material into the retort will now be described, special reference being had to Figs. 2, 5, l5 and 16.

It has been found that when attempting to feed finely divided material from a hopper, as for example by means of a discharge screw or a plunger, trouble is often experienced by reason of Apacking and arching of the material in the hopper. It has also been found that in feeding such materials by means of a piston and cylinder communicating directly with a hopper, the material is likely to become jammed or packed in the cylinder, with resultant strain or damage to the apparatus.

In designing my improved mechanism, I have succeeded in obviating both of the foregoing difculties, first, by avoiding the use of a hopper containing a fixed mass of material, and second, by delivering predetermined quantities of material into the discharge cylinder.

My improved apparatus comprises a vertically disposed housing or chute having an opening |00 at its upper end, into which the material to be treated is preferably fed continuously. At the lower end of the chute or housing is a discharge opening formed by the walls |b and |000, the

.-chute itself and associated mechanism being supported on a pair of spaced beams 10a supported on the cross beams 11.

vMounted within and projecting from the chute or housing above described is a horizontal trough |0| of uniform width throughout, such 'trough ybeing supported for free reciprocating movement on two pairs of rollers |02, one pair mounted on a shaft extending between the side walls |00' of the chute, and the other pair on a similar shaft extending between a pair of guide plates |01, referred to below. The trough |0| passes through an opening in the wall of the chute provided with alflange |005, and adjacent this opening the side walls of the trough |0| are extended upwardly as at |0|a and these extended portions are provided with a cover |03 and with a back plate Secured to and extendingY between the sid walls |00 of the chute is a horizontal plate |05 positioned so that its upper surface substantially coincides with the plane of the upper edges of the trough, and attached to this plate |05 is an rangle bracket having its vertical leg |06 of substantially the same shape as the cross section of and fitting within the trough.

The trough |0|, at its forward or discharge end |0I, passes between a pair of guide plates |01, extending upwardly from a chamber |08,

' from which chamber extends a delivery pipe or flanges ||4 depending from the bottom of the trough .|0I., The lug is also adapted to engage a cross wall ||5 at the forward end of the anges ||4, and in fact the lug may be said to play between the pin ||2 and the Wall H5. The plunger or piston I0 is held in proper position by means of a pair of auxiliary plungers ||094 disposed one at each side of the piston and rigidly secured to a bracket ||0c formed integral therewith. The plungers ||0EL work in xed guides ||0b and thus maintain the piston at all times in axial alignment.

Also formed integral with the bracket ||0c is a boss ||0d in which is set a pin ||6 to the lower end of which is attached one end of a connecting rod ||1, the other end of which is attached to a similar pin ||8 set in a crank arm ||9 secured to the upper end of a vertical shaft |20 journalled in a bearing bracket |2|. Beneath this bracket, the shaft |20 is connected by a suitable universal joint with the upper end of a hollow shaft |205, which extends down to the rotating and discharging mechanism hereinafter described.

Referring to Fig. 5, I mount in an inclined position within the housing 8| just in front of the end of the delivery conduit |09, a pressure plate |09', pivoted'at its upper end at |00a and having secured to its lower edge adjustable weights |09b, the number of which may be varied as desired.

The operation of the feeding mechanism above described will now bie briefly set forth. The nely divided material is fed continuously into the upper end |00 ,of the feed chute, passing down into the trough |0I, filling and overflowing the same, and then passing out of the bottom of the chute, from which point it may be returned by a suitable conveyor (not shown). Meanwhile, the piston ||0 is being reciprocated by means of the connecting rod ||1, and the lug causes a similar reciprocation of the trough |0I.

The wall ||5 is so positioned that, at the eX- treme forward position of the piston I0, in which position its forward end enters the end of the conduit |09, the discharge end |0I' of the trough |0| registers substantially with the forward edge of the cylinder |08. With the pin H2 in its extreme forward position, as shown in Fig. 15, the trough is retracted, when the piston moves back, into the position shown. Thus, the piston and trough reciprocate together except for a slight lost motion due to the space between the pin l2 and wall I5. Starting with the trough in the position shown inthe drawings, the material entering the top |00 of the chute will nll and overflow the trough at a point immediately in front of the Xed angle bracket |09, this material entering the trough between the xed plate |05 and the movable vertical plate |00. Upon forward movement of the trough from this position, more material falls in behind that which is already there and in front of the angle bracket |08. Upon backward movement of the trough, this material is pushed forward by the angle bracket |00, and at the same time the vertical wall or stripper plate |00 serves to level off the material in the trough so that the material is never heaped up in the trough-at any point forward of the stripper plate, but the trough is maintained level full, the coverplate |03 preventing any material entering the trough in advance of the stripper plate |04.

- It was stated above that as the trough moved rearwardly, the angle bracket |06 pushed the material forward in the trough. It would be more accurate to say that as the trough moves rearwardly, the angle bracket holds the material in the trough stationary while the trough travels back beneath this mass of material.

Upon successive reciprocations of the trough, additional quantities of material enter the rear portion thereof until the trough becomes full throughout its entire length in front of the bracket |06. After the trough has become full, it will be apparent that, upon the next return or rearward movement, a measured quantity of material is discharged from the forward end of the trough into the cylinder |08. This measured quantity represents a mass of a section equal to the cross section of the trough and of a length equal to the stroke thereof.

With the pin I |2 in the position shown in Fig. 15, the device is set for delivering the maximum quantity of material at each stroke, that is to say, a batch of material occupying a lineal distance in the trough equal to the full width of the chamber |08 is forced from the end of the trough and drops into the chamber. If it be desired to feed smaller batches or measured quantities of material, the pin ||2 is placed in one of the other holes ||3, further toward the rear. In this case, the trough |0| will be moved to the same extreme forward position, but, on its return stroke, will be moved only part way back, that is to say, the delivery end IBI', instead of being retracted to the position shown in Fig. 15, will stop at some intermediate position in which it partly overhangs the open top of chamber |08. The volume of the batch of material delivered at each stroke is, of course, proportional to the length of the stroke of the trough or, in other words, to the longitudinal dimension of the mass of material which is ejected from the end of the trough upon its return stroke.

From the foregoing, it will be understood that the material is fed into and through the chute at a rate in excess of the maximum rate at which it is to be delivered into the retort, and that the reciprocating trough serves to intercept a portion of the stream of material passing through the chute and deliver such intercepted portion in the form of successive batches of predetermined volume in front of the piston I0. In this way, the difficulties heretofore experienced in the feeding of nely divided materials from filled hoppers is avoided on the one hand, and on the other hand, thel danger of overfeeding material in front of the piston and thus producing abnormal stresses in the mechanism is eliminated. With my improved arrangement, the volume of material deposited in front of the. piston is automatically limited.

Referring again to Fig. 5, the material forced by the piston ||0 out of the cylinder |08 passes into and through the conduit |99, and finally accumulates against the weighted pressure plate |09. When the space within the conduit and beneath the pressure plate. becomes completely lled with material, the pressure of the piston causes the plate |09 to swing upwardly on its pivot at each stroke and permit a definite amount of material to pass and to be discharged through the opening la and down the chute 80, it being understood that at each stroke of the piston the same amount of material is` forced past the pressure plate |09 as is delivered by the trough |0| into the cylinder |08.

The purpose of the pressure plate, therefore, is

to maintain the delivery conduit |09 completely lled with a compact mass of material, so as to form a substantially tight seal to prevent the escape of gaseous products out through the feed mechanism.

Driving and discharge mechanism At its lower endy the hollow shaft |a is connected by a suitable universal joint to the upper end of a vertical shaft |22 journalled in bearings |23 carried by the top of a gear casing |25, and bearings |211 mounted within said casing, which casing is supported on the base plate 3. Between the bearings |23 and |24, there is rigidly secured to the shaft |22 a bevel gear |26 meshing with a, similar gear (not shown) secured to a drive shaft |221 (Fig. 3) connected with variable speed reducing gearing |28, driven by a motor |28', the speed of the shaft |21' being regulated by means of a control la.

On the lower end of the shaft |22, below the bearing |24, is secured a pinion |29, which meshes with a gear |30, secured to a short vertical shaft |3|, journalled in suitable bearings and carrying at its lower end gear |32. The gear |30 meshes with and drives the ring gear |2 secured to the rotating cylindrical shell of the retort, as above described, and. the gear |32 meshes with a gear |33, secured to the upper end of a vertical shaft |34. This shaft is journalled in bearings formed in a short cylindrical casing having upper and lower parallel walls |35 and |40. Fitting snugly between these walls and within the cylindrical sides |38 of the casing is a discharge wheel comprising a hub |39, and a plurality of spokes |3!la radiating therefrom (Fig. 20), these spokes, in combination with the cylinder |38, forming closed cells.

Atv the side adjacent the retort, the top plate |36 has an opening |4`| adapted to register successively with the cells between the spokes |39n as the discharge wheel rotates, and on the opposite side of the casing, the bottom plate |40 is provided with a vertical discharge opening |4|a, with which the cells in the discharge wheel are likewise adapted. to successively register (Fig. 4). The lower end of shaft |34 preferably is supported on the end of an adjustable bearing screw |34? By this means, the discharge wheel may be accurately positioned between the upper and lower plates |36 and |40, and prevented from dragging upon the lower plate.

Formed in the bottom plate 3 at a point directly above the opening |4| is a discharge opening 3e, and a chute |42 is arranged to conduct the material from the opening 3a and deliver it into the opening |4|.

General operation Power being supplied by the motor 2S, the vertical shaft |22 and with it the hollow shaft |20a and vertical shaft |20 is driven and through the gears |29 and |30 and ring gear |2 the cylindrical shell of the retort is rotated. This shell carries with it, in its rotation, not only the various conveyor elements which are connected to it by lugs or drag chains, but also the plate 90, cylinder 92, and Scrapers 94 carried at the top of the apparatus. The stack of heating elements, and all other parts of the superstructure are, of course, stationary.

The material being fed into the housing 8|, as above described, is discharged downwardly through the opening 15a-and chute 80, into the cells of the topmost conveyor element.

It will be noted that since the feed mechanism and the cylindrical shell rotating mechanism are geared together, they operate with a constant speed ratio, and by properly selecting this ratio, it is possible to so arrange the apparatus that a measured batch of material is delivered from the lower end of the chute 80 each time a cell of the conveyor element passes under the chute. In

other words, successive measured batches of material are delivered into successive cells as the topmost conveyor element rotates.

As in my prior patent, above identified, the material falls, cascade fashion, from one heating element to another, passing through the openings or notches 38, which notches are oifset from each other and arranged in the form of a spiral. It will be understood that the direction of rotation of the shell and conveyor elements is clockwise, as indicated by the arrow in Fig. 3 and Fig. 10, the successive notches in the heating elements being oiset in the direction indicated in Fig. 10. In this way, the material deposited on one heating element makes fteen-sixteenths of a complete revolution before being discharged through the notch onto the heating element next below. Thus, in Fig. 2, the notch 38 in the tolpmost heating element is displaced in a counter-clockwise direction one-sixteenth of a revolution or 221/2 from the chute 8U under the housing 8 l at which point the material is deposited, and each successive notch, progressively down the series of heating elements, is displaced 221/2 in a counter-clockwise direction from the position shown at 38 in Fig. 2, until the notch 38 in the lowermost heating element, as shown in Fig. 4, is directly under the housing 8| (Fig. 2) Where the material enters the retort.

The spent material discharged from the lowermost heating element passes through the opening ila in the base plate and thence through the chute |42 into the discharge wheel |39, whence it is delivered from the discharge opening Idle. The discharge mechanism, above described, in which the material enters the cells at one side of the vcylindrical casing and is discharged from the opposite side thereof, provides a gas tight seal to prevent the passage of gaseous products therethrough. It will be noted that the discharge mechanism is also geared to the shaft 22 so that it is always driven at a speed which bears a xed ratio to the rotation of the main cylindrical shell and the operation of the feed mechanism. 'I'he capacity of the cells |39a in the discharge wheel is ,preferably somewhat greater than the volume of the maximum measured batches of material fed into the retort at the top.

Since measured batches of material of uniform volume are successively fed into the cells of the Auppermost -conveyor element, it will be seen that when these cells are filled (either partly or wholly full, depending upon the stroke of the feeding mechanism, as above explained) the material therein is in the form of a layer of uniform thickness, and the rotation of the conveyor elements causes this layer to slide along in contact with the upper surface of the heating elements. I have found that this method of subjecting iinely divided material to indirect heat, namely, by confining it within cells having closed sides, or, in the form of a layer of uniform thickness, and causing this layer to slide progressively over the surface of a hot plate, is a very eicient one and possesses marked advantages.

Inasmuch as the rotating means, feeding means ,and discharging means are all geared together,

it is possible tovary the time during which the material is subjected to the action of heat without varying the thickness of the layer of material or making any other relative adjustments. This may be done simply by manipulating the control I28f of the variable speed drive I28, in order to vary its speed.

One of the chief practical diiliculties in the processing of nely divided resinous wood and other materials of this nature is the tendency of such materials to cake or coke under the influence of heat, and adhere to the surfaces with which they are in contact. Thus, in continuous retorts of the type described herein, in which the material is intended to fall by gravity through the openings or notches in successive heating elements, it frequently happens that owing to caking or coking, the material clings to the side walls of the conveyor element and is not discharged therefrom by gravity when it passes over the openings in the heating elements. This resuits in interrupting the flow of material through the retort and jamming or choking of the apparatus.

One of the important features of the present invention is the provision of means for forcibly ejecting caked masses of material from the con-V veyor cells. 'I'his is the purpose of the arcuate ribs 4i] having the lower inclined surfaces 40a, as shown in Figs. 6, 7 and 10'. By reference to Fig. l0, it will be observed that these ribs are carried by the lower face of each heating element and overlying the notch or opening 38 of the heating element next below, the lowest point of the inclined surface of the ribs being immediately above such opening, It will further be observed by reference to Fig. l0 that the depth,

of the ribs increases progressively in the direction of rotation of the conveyor elements, as shown by the arrow, and the lowest point lies slightly above the plane of the upper surface of the conveyor element.

As long as the material remains as a layer of uniform thickness in the cells of the conveyor element, or as long as it does not project above the upper surface of such cells, the ribs 40 have no effect. If, however, the material should fail to fall out of any cell as it passes over the opening in the heating element, and this cell should travel around again and receive another charge of material on top of that already in the cell, so that the material is heaped up in the cell, as shown in Fig. 10, then when this mass of heaped up material is carried `underneath the inclined surface of the ribs 40, such inclined surface will serve to force the material downward and eject it from the cell through the opening below, breaking up any caked masses and disengaging them from the side walls of the cell. Experiments have shown that no matter how badly the material may be caked in a cell, the device just described will serve to effectively break it loose l and clear the cell for receiving the next charge.

lViy improved means for circulating a gaseous heating medium through the heating elements and means for controlling the temperature of the gaseous heating medium are especially important features of my improved apparatus. Referring to Figs. 3, 4, 5, 17, 18 and 19, it will be seen that the fan 6l is in series with the flue passages formed by the base of the apparatus and the plurality of heating elements supported thereby, It will thus be understood that hot gases from the furnace 5B are delivered into the radial duct 54, (Fig. 4) from which they pass into the annular space within the base and thence upwardly through the supporting ring into the interior of the lowermost heating element 21, and thence successively upward through the interiors of each heating element in turn. It will be observed that the position of the baffles 33 is such that the hot gases are caused to follow a radially zig-zag path, flowing outwardly over the bottom wall of the heating element and thence radially inward along the upper wall.

As shown in Fig. 5, the hot gases emerging from the uppermost heating element, and passing around the topmost baille 33, fiow downwardly through the central axial conduit formed by the cylindrical sections 112, and thence, as shown in Fig. 1'1, out through the axial pipe 45, radial duct d, and discharge flue 62, to the fan El (Fig. 3) from which they are delivered back again through the pipe 58 (Figs. 3 and 18), into the conduit 55, thus making a complete circuit through the conduit system including the flue passages within the heating elements.

This arrangement of a complete circuit of iiue passages in series with a circulating fan, but independent of the furnace, is one of the vital features of my improved retort, and it is important that the cross-sectional area of the flue passages composing the circuit be amply sufficient to permit the ready circulation of large volumes of gases through them As has already been described, the circuit of flue passages comprises an inlet duct or nozzle 51 (Fig. 4), and an outlet duct or discharge stack 60, branching therefrom. (Figs. 3 and 18). The amount of gas expelled by the fan Gl through the outlet duct 60, may, as above explained, be

. regulated by means of the damper 63. Each foot of gas expelled through outlet 6G under pressure is replaced by a similar amount drawn inward through duct 51, by the partial vacuum created at the intake of the fan, which incoming gas is derived from the combustion of fuel in the furnace 56.

If the damper 63, (Fig. 18) is set so that the outlet 6D is completely closed, then there is no inflow of gas through duct 51 and no inflow of air through the draft openings 55h of the furnace and therefore no combustion of fuel within the furnace. Consequently there would be no additional heat being introduced into the mass of gas being circulated by the fan through the closed circuit of flue passages just described, including the heating elements. However, at all times that the fan 6| is in operation, a large volume of gas is being circulated through the heating elements and around the closed circuit of flue passages, exclusive of the furnace, as described, that is to say, the` same gas, after passing up through the heating elements, is forced by the fan to recirculate therethrough again and again, Under these conditions, the temperature of the heating elements is relatively low.

When, however, the damper 63 is opened to a slight degree, as illustrated, for example, in Fig. 18, thus deiiecting through the discharge outlet some of the gases being circulated by the fan, a certain amount of air will enter the furnace chamber through the draft openings 56h, which air may support the combustion of a denite amount of fuel injected into the furnace through the burner 56e. The gases resulting from the combustion of this definite amount of fuel must be enough in volume to compensate for the volume of gas being expelled by the fan through the discharge outlet 60. It will thus be seen that each setting of the damper 63 requires such an adjustment of the burner 5Sa as will result in the production of a corresponding volume of high temperature gases of combustion, which gases flow from the furnace through the nozzle 51 and mix with the stream of gases being circulated by the fan at high velocity through the heating elements as described.

With the damper E3 set in its lowermost position, there would be no recirculation of gases at all, as the entire volume passing through the fan would be drawn in through the draft openings 56b of the furnace and expelled through the discharge stack 69. This would afford a maximum supply of air for the combustion of the maximum amount cf fuel, thus producing the conditions for maximum temperature of the gases passing through the heating elements. Such maximum temperatures are usually undesirable and a major purpose of my improved method of limiting the combustion of fuel by the setting of the damper 63 is to guard against undesirably high temperatures.

In actual operation of the apparatus, a desirable maximum temperature for the circulating of hot gases at the point where they enter the lowermost heating element would be selected, a suitable pyrometer (not shown) being mounted at this point to indicate the temperature. This desired maximum temperature is then obtained by starting the circulating fan 6|, adjusting the damper 63 so as to induce a flow of air through the draft openings 5th, then adjusting the burner 56a so as to obtain the efficient combustion of the fuel injected by it. Then the amount of fuel being burned may be increased or decreased by successive adjustments of the damper 63 and the burner 56a until the desired maximum temperature of the circulating gases as indicated by the pyrometer is obtained and maintained. When equilibrium is reached, as indicated by a substantially constant reading of the pyromcter, it is obvious that the heat generated by the combustion of fuel is just sufficient to compensate for the heat being transmitted and lost through the walls of the heating elements and being discharged by the fan through the stack 60.

Thus the apparatus may be set for perfect combustion of the fuel. This insures production of a non-oxidizing circulating medium, and it will be noted that there is no dilution of the circulating gases with air, at any time.

It remains to describe the path of the vapors and gaseous products given off from the material being processed. It is preferable that the heating elements be thoroughly heated prior to the introduction of the material being processed, and that the mass and temperature of the heating gases being circulated through the heating elements be such that the desired temperature of the heating elements is maintained after the processing of the material is started. It has been found that a highly satisfactory temperature range for the circulating heating gases is that they should enter the bottom heating element at approximately 1,300 degrees F., and return to the circulating fan at approximately 900 degrees Fahrenheit. This temperature range keeps the topmost heating element at substantially the temperature at which the carbonization of wood pro gresses as an exothermic reaction.

As above pointed out, the nely divided wood or other material is fed in at the top of the retort in successive measured amounts to form a layer within the rotating topmost conveyor element,

www

which moves the layer, without substantial agitation, of the particles composing it, in sliding contact with the top surface of the heating element.

Each conveyor element delivers the material cari ried by it, in cascade fashion, to the next lower conveyor element and thus the stream of material being processed is successively moved over the surfaces of the entire number of heating elements; each succeeding lower element being .progressively of higher temperature. In cascading from one heating element to the next lower element the `particles composing each layer of the material being processed are substantially rearranged. The porous layers of finely divided particles are very poor conductors of heat and only those particles in direct contact with the top surface of the heating element are subjected to a rapid rise in temperature. These contacting particles, however, Very quickly approach the temperature of the heating element. It has already been observed that it is preferable to have all the heating elements maintained at temperatures in excess of the temperature required to produce the .exothermic breakdown of the material, viz, approximately 850 degrees F. in the case of wood. The particles of each layer contacting the heating element, therefore, are Very quickly carbonized and the resultant vapor and gaseous products move vertically away from the surface of the heating element and flow through the superimposed porous layer of cooler particles, and rapidly transfer their heat, in the case of vapors, by condensation. With each transfer of the porous layers of material from one heating element to the next lower heating element, fresh particles of wood or other material are brought in contact with the surface of the heating element and in turn are rapidly carbonized with a continued movement of the gaseous and vapor products upward through the cooler material with consequent condensation and transfer of heat to the cooler materials. As the temperature of the entire porous layer of material -is rapidly increased by this dual method of heating, reevaporation of the liquids, resulting from the previous condensation of vapors, takes place. The dual method of heating, above referred to, includes heating by conduction from the hot surface of the heating elements, and heating by the exothermic reaction brought about by the breakdown of the material r particles in contact with the heating element, the exothermic heat being stored in the vapor and gaseous products. In the above mentioned'reevaporation, the lower boiling liquids are rst vaporized and the higher boiling liquids remain mixed with the particles composing the layer. There is thus an accumulation of high boiling liquids in the layer as it rapidly approaches the critical temperature at which the remainder of wood particles contained in it break down with a further liberation of exothermic heat. The presence of the accumulation of high boiling liquids in the layer serves to absorb this exothermic heat as heat ci' vaporization, thus serving to quickly `cool the vapor products of carbonization to a degree that materially inhibits cracking.

The vapors and gases which escape from any layer of material iiow to the opening 38 in the heating element immediately above the layer of material and mingle with the stream of gases and vapors from other layers of material flowing upward through the broken spiral passage way formed by the said openings in the heating elements, and moving through zones of progressively decreasing temperature, thus further inhibitinglthecrackirig of the vapory products.

The..` greater part of -the gaseous products emerge through the opening 33L in the topmost heating element, this opening being in the position shownindotted lies inFig. 2. The products then mostly flow around the annular chamber between the cylinders 18 and 19, in a counterclockwise direction, as indicated by the dotted arrow in Fig. 2, and pass into the opening at the diametrically opposite side of the retort.

From the opening 88,.the gaseous products pass upwardly into the cylindrical chamber 82, and are-then discharged radially therefrom through the conduit 9S. Thus the gaseous products flowing through the superstructure, as above described, areY caused to sharply change their direction at a number of points. This sudden change in'direction tends to causeany solid particles entrained or carried Valong with the gases ,to be deposited either in the trough 81 orv on the vwalls of the cylindrical chamber 32, and, as above described, such deposited materialis continuously removed by the rotating scraper blades, and returned to the topmost conveyor element.

My process, which has nection with the movement of finely divided woods and other. similar materials, over a'succession' of hot heat-conducting surfaces in the order of ascending temperature, opens a broadly interesting field of modifying vapor products of destructive distillation by contacting them with acid or" other vapors derived from materials added to the finely divided Wood priorto its introduction into my apparatus, and by contacting them with active gases such as chlorine or sulphurl dioxide which may be admitted in controlled amounts at the base of the apparatus. Various catalytic agents may also be added'to the finely divided materials being processed and the aggregate layer of material subjected to the action of heat delivered by direct contact of the material with the heat conducting surface.

`While in the claims I have used the word retortin defining the invention, it will, of course, .be understood that this term is intended to be broad enough to include apparatus for drying or otherwise processing material, as well as for subjecting the same to destructive distillation.

Many of the features set forth in the'preamble and illustrated and Vdescribed in detail in the specification and'drawings are not claimed herein but form the subject matter of my copending divisional applications Serial No. 427,661, led January 2l, 1942, and Serial No. 470,471, filed Decem- 'ber 29, 1942.

What I claim is:

1. The combination with a retort, of a conduit, one end of which is connected therewith at one point, a source of hot gases separate from said retort delivering into the other end of said conduit, a flue connected with said retort at another point, a pipe communicating with said flue and tapping said conduit at a point between its ends, means independent of said source for causing a forced circulation of gases through said conduit, retort, flue, and pipe, and means for deecting and ejecting from said pipe at a pressure above atmospheric a portion of the gases flowing therethrough.l v l V Y 2. The combination with a retort, of a conduit, one end of which is connected therewith at one point, a source of hot gases separate from said retort delivering into the other end of said conbeen described in con- 

